Laser Safety Manual Prepared by: Chemical Control Centre 401 Sunset Avenue Windsor, Ontario N9B 3P4 e-mail: ccc@uwindsor.ca web: uwindsor.ca/laser phone: 519.253.300 ext. 3523 Last Review: 08/28/2017
Table of Contents LAST REVIEW:... 1 TABLE OF CONTENTS... 2 GLOSSARY... 4 1 LASER SAFETY PROGRAM... 5 1.1 OVERVIEW OF LASER USE AT THE UNIVERSITY OF WINDSOR... 5 1.2 LASER PROGRAM OBJECTIVES... 5 1.3 REGULATIONS... 5 2 LASER COMPONENTS AND CHARACTERISTICS... 6 2.1 LASER PROPERTIES... 6 2.2 LASER COMPONENTS... 7 2.2.1 Active Medium... 7 2.2.2 Excitation Mechanism (Energy Source)... 7 2.2.3 Optical Resonator... 7 3 LASER HAZARDS... 8 3.1 EYE HAZARDS... 8 3.2 SKIN HAZARDS... 10 3.3 FIRE HAZARDS... 11 3.4 NON-BEAM HAZARDS... 11 3.4.1 Electrical Hazards:... 11 3.4.2 Chemical Hazards:... 12 3.4.3 Inhalation Hazards:... 12 4 LASER AND LASER SYSTEM CLASSIFICATION...12 5 HAZARD EVALUATION...14 5.1 VIEWING CONDITIONS OF LASER RADIATION... 14 5.2 MPE - MAXIMUM PERMISSIBLE EXPOSURE (J/CM2 OR W/CM 2 ) FOR IRRADIANCE... 15 5.3 NOMINAL HAZARD ZONE... 15 6 LASER SAFETY PROGRAM COMPONENTS...16 6.1 ORGANIZATION: ROLE AND RESPONSIBILITIES... 16 6.1.1 Permit Holder / Laser Supervisor:... 16 6.1.2 Laser Worker:... 17 6.1.3 Team Leader, Chemical Control Centre (Laser Safety Officer)... 17 6.1.4 Manager, Environmental Health & Safety (Senior Laser Safety Officer)... 18 6.1.5 Research Safety Committee (RSC):... 18 6.2 TRAINING... 19 6.3 EYE PROTECTION POLICY... 19 6.4 INTERNAL PERMIT PROCEDURE... 20 6.4.1 Application for Laser Internal Permit Procedure:... 20 6.4.2 Permit Amendment/Renewal Procedure:... 20 6.4.3 Standard Operating Procedures Policy:... 20 6.4.4 Location and Operation Policy:... 21 6.4.5 Purchase and Disposal Policy:... 21 6.4.6 Medical Surveillance Policy:... 21 2
6.5 SUSPECTED OF KNOWN LASER INJURY... 21 6.6 SECURITY AND CONTROLLED ACCESS OF CLASS 3B AND 4 LASER... 21 6.7 SAFETY PROCEDURES... 22 6.7.1 Class 1 Lasers Safety Procedures:... 22 6.7.2 Class 2 Lasers Safety Procedures:... 22 6.7.3 Class 3 Lasers Safety Procedures:... 23 6.7.4 Class 4 Lasers Safety Procedures:... 24 6.8 LASER CONTROLLED AREAS... 24 6.8.1 Class 3B Laser Controlled Areas:... 25 6.8.2 Class 4 Laser Controlled Areas:... 25 6.8.3 Other Laser Controlled Areas... 26 6.8.4 Temporary Laser Controlled Areas... 26 6.9 INSPECTION OF CLASS 3B/4 LASERS... 27 6.10 COMPLIANCE ENFORCEMENT POLICY... 27 6.10.1 Minor Offence Actions:... 27 6.10.2 Major Offence Actions:... 28 APPENDIX...30 3
Glossary ANSI American National Standard Institute CCC Chemical Control Centre LSO Laser Safety Officer MPE Maximum Permissible Exposure NHZ Nominal Hazard Zone RSC Research Safety Committee 4
1 Laser Safety Program 1.1 Overview of Laser Use at The University of Windsor The use of lasers has become more prominent on campus, often occurring in locations and applications that one would not expect to find them or believe that a hazard might exist. A wide range of laser applications occur on campus, including laboratory research, cutting, imaging, printing, welding, communications, measurement, and entertainment. Research laboratories use lasers for spectroscopic and other physical and chemical applications. They can be used to determine the chemical composition of substances and measure concentrations of chemicals to high precision and accuracy. In addition, lasers are used as catalysts in some chemical reactions. 1.2 Laser Program Objectives The principle objectives of the University of Windsor s laser safety program laser safety are: 1. To mitigate the risks associated with the utilization of lasers in both our teaching and research programs. The human eye is the most sensitive organ, making it prone to damage caused by laser beams. In addition, lasers operating at high power levels can cause burns to the skin. Reducing human exposure to the laser beam and its associated hazards will lessen these risks. 2. To conform to the requirements of the Ontario Ministry of Labour, the American National Standard for Safe Use of Lasers (ANSI Z136.1-2007) and related regulations and standards. Low power lasers are very common in every workplace, including lasers that are enclosed within a piece of equipment such as a CD player or laser pointer. A safety program is not required for these types of lasers as they do not pose a hazard to individuals within the workplace. However, in some cases a moderate or higher power laser is utilized for a specific application thereby making a laser safety program a requirement. 1.3 Regulations Lasers are regulated by the Ontario Ministry of Labour (the Ministry), which is responsible for ensuring that employers take adequate steps to protect the welfare of its employees. Under the Occupational Health and Safety Act and Regulations (1990) an employer is responsible for taking every precaution reasonable in the circumstances for the protection of the worker, including when operating lasers. Currently, there is no specific regulation developed by the Ministry for the safe utilization of lasers in the 5
workplace; however, their inspectors use the American National Standards Institute (ANSI) standard for safe use of lasers (ANSI-Z136.1-20014) to stipulate the proper control and training mechanisms that are to be utilized in the workplace. The University of Windsor s Laser Safety Program is based on this standard. 2 Laser Components and Characteristics 2.1 Laser Properties The term "laser" is an acronym that stands for "Light Amplification by Stimulated Emission of Radiation". Laser light is a form of non-ionizing radiation. Laser equipment produces and amplifies light that has unique properties that cannot be produced by other means. The light that is produced is monochromatic - it is composed of a single colour at a specific wavelength. Light from other sources is made up of combination of colours at various wavelengths. Laser radiation can be generated in different parts of the spectrum - ultraviolet (UV), visible, and infrared (IR) (Figure 1). The color of laser light is usually described in terms of the wavelength of the laser radiation (e.g., red, green). The most common unit used for the wavelength of laser is a nanometer (nm - one billionth of a meter). Another property of lasers is they are coherent light sources. This means that lasers produce monochromatic light (i.e., with a single or selected wavelength) in which the light particles or photons all travel in the same direction. This allows laser beams to be very focused (collimated) so they do not fan out like the light beam of a flashlight. Since the light energy can be contained in a very narrow beam, it has a high radiant power per unit area. These properties enable laser devices to produce powerful beams that can even cut metal. Lasers are also used in medicine for cutting, sealing and other surgical procedures. Figure 1: Electromagnetic Spectrum. Most lasers in research utilize the spectrum in the Ultraviolet, Visible, and Infrared (http://www.cyberphysics.co.uk/topics/light/emspect.htm) 6
2.2 Laser Components All lasers contain three primary sections (Figure 2): 2.2.1 Active Medium The active medium contains atoms, molecules or ions whose electrons may be excited to a metastable energy level by an energy source to produce laser light. The active medium can be either solid crystalline materials such as ruby, or solutions of organic dyes, or gases such as Helium/Neon, or semiconductors such as Gallium/Aluminium/Arsenic. The material determines many of the laser beam s output characteristics, including its wavelength. There are four major types of lasers based on the lasing medium: Solid State Lasers o E.g. ruby laser, Nd:YAG (Neodymium:Yttrium/Aluminum/Garnet) Semiconductor or Diode Lasers o E.g. GaAlAs (Gallium/Arsenic/Arsenic) Liquid (Dye solution) Lasers Gas Lasers o E.g. Carbon dioxide, rare gas-halogen, nitrogen 2.2.2 Excitation Mechanism (Energy Source) The excitation mechanism is determined by the input energy device which pumps energy into the active medium. The energy source can be optical, electrical or chemical. 2.2.3 Optical Resonator The optical resonator consists of two specially designed mirrors. The high reflectance mirror reflects essentially 100% of the light hitting it while the other partially transmissive mirror (called the output coupler) reflects less than 100% of the light hitting it and transmits the remainder. Energy Source 7
Figure 2: Laser Components 3 Laser Hazards 3.1 Eye Hazards Corneal or retinal burns (or both) depending upon laser wavelength, are possible from acute exposure. Corneal or lenticular opacities (cataracts), or retinal injury may be possible from lengthy exposure to excessive levels of short wavelength light and ultraviolet radiation due to photochemical effects. Ocular hazards represent a potential for injury to several different structures of the eye. Ocular injury from heating is generally dependent on which structure absorbs the most radiant energy per volume of tissue. Photochemical injury also depends upon the energy per photon of the energy absorbed (i.e., shorter wavelength radiant energy has more energetic photons). Retinal effects are possible when the laser emission wavelength occurs in the visible and nearinfrared spectral regions, which is 400 to 1400 nanometers. Light directly from the laser or from a specular (mirror-like) reflection entering the eye at these wavelengths can be focused to an extremely small image on the retina. The incidental corneal irradiance (or radiant exposure) will be increased approximately 100,000 times at the retina due to the focusing effects of the cornea and lens (Figure 3). Figure 3: Simplified Cross Section of the Human Eye (https://www.laserfx.com, 2015) The eye is the most vulnerable to injury from the laser beam. The potential for injury depends on the power and wavelength of the laser beam (light). Intense, bright, visible 8
light makes us blink as a reflex reaction. This closing of the eye provides some degree of protection. However, visible laser light can be so intense that it can do damage faster than a blink of an eye. The invisible, infrared laser beam, such as that produced by a carbon dioxide (CO2) laser, does not produce a bright light that would cause the blinking reflex or the pupil to constrict and, therefore, chances of injury are greater compared to a visible light beam of equal intensity. The location of the damage depends on the optical nature of the laser beam. Lasers in the visible light and near infrared range focus on the retina (Figure 4). Therefore, the injuries produced are retinal burns. The infrared radiation is absorbed in the cornea and may cause corneal damage and loss of vision. Figure 4: Ocular Absorption Site vs. Wave length: The wavelength of the laser affects eye damage (https://www.phys.ksu.edu/, 2015) Actinic-ultraviolet, at wavelengths of 180 to 315 nm, is absorbed at the cornea. These wavelengths are responsible for welder s flash or photokeratitis (injury to the cornea). Actinic-ultraviolet radiation also produces sunburn or erythema (reddening) of the skin. Near-ultraviolet (UV-A) radiation between 315 and 400 nm is absorbed in the lens and may contribute to certain forms of cataracts. At high irradiances, these wavelengths also produce long-wave erythema of the skin and photokeratitis. Radiation at visible (400 to 700 nm) and near infrared (700 to 1400 nm) wavelengths is transmitted through the ocular media with little lose of intensity and is focused to a spot on the retina 10 to 20 micrometers (μm) in diameter (1 micrometer (μm) is one tenthousandth of a centimeter). Such focusing can cause intensities high enough to damage 9
the retina. For this reason, laser radiation in the 400 to 1400 nm range is termed the retinal hazard region (Figure 5). Wavelengths between 400 to 550 nm are particularly hazardous for long-term retinal exposures (i.e., exposures lasting for minutes or hours). This photochemical effect is sometimes referred to as the blue light hazard. Far-infrared (IR-C) radiation with wavelengths of 3000 nm to 1 millimeter is absorbed in the front surface of the eye (the cornea). However, some middle-infrared (IR-B) radiation between 1400 and 3000 nm penetrates deeper and may contribute to glass blower s cataract. Extensive exposure to near-infrared (IR-A) radiation may also contribute to such cataracts. The localization of injury is always the result of strong absorption in the specific tissues for the particular wavelength. Figure 5: The Retinal Hazard Region. The illustration also shows the most common lasers used in research as well as their operational wavelength (nm) (https://www.cpsafety.net, 2015) 3.2 Skin Hazards The potential for skin damage depends on the type of laser, power of the laser beam, and the duration of exposure. The type of damage may range from localized reddening to charring and deep incision. Skin effects are generally considered of secondary importance except for ultraviolet and higher-power lasers. Sunburn, skin cancer and accelerated skin aging are possible in the 230 to 380 nm wavelength ranges (0.23 to 0.38 μm-actinic ultraviolet). The most severe effects occur in the UV-B (290 nm 315 nm). Increased pigmentation can result following chronic exposures in the 290 to 400 10
nm wavelength ranges. In addition, photosensitive reactions are possible in the 310 to 400 nm (near ultraviolet) and 400 to 600 nm (visible) wavelength regions. Bioeffects in the 700 to 1000 nm (infrared) regions will be skin burns and excessively dry skin. Protective clothing (gown, cap, mask), gloves, and safety eyewear for the specific wavelength of laser energy may be required for working near a laser. Consult manufacturer's operating procedures and check with the LSO to determine the specific needs for personal protective equipment and clothing. 3.3 Fire Hazards A fire can be started when a laser beam or a reflection of the beam strikes a combustible material such as rubber, plastic, human tissue, paper products, skin treated with acetone and alcohol-based preparations, human hair, and intestinal gases. Fire hazards are of particular concern in oxygen-rich atmospheres when oxygen or nitrous oxide is being used. 3.4 Non-Beam Hazards 3.4.1 Electrical Hazards: The only reported deaths that have occurred during laser operations have not been caused by beam exposure but have been related to non-beam hazards, such as electrocution. Laser systems can require a significant amount of power, which poses a risk to operators. In addition, more powerful lasers can start fires or cause explosions if the beam comes into contact with flammable or combustible materials. Many lasers use high voltage and high current electrical power. The danger of electrical shock or electrocution arises when an untrained or unauthorized person tries to perform maintenance work without following the proper safety procedures. The ANSI standard Z136.3 outlines electrical safety procedures applicable to laser equipment. Electrical safety requirements include the following: Use proper grounding for metal parts of the laser equipment. Label laser equipment with electrical rating, frequency and wattage. Prevent explosions in high pressure arc lamps and filament lamps. Avoid contact with electrical components, including capacitors, that can contain an electrical charge even after the power is turned off. Ensure that combustible components of electrical circuits are short circuit tested. Make sure that there is no electromagnetic interference between the laser equipment and other electrical equipment. 11
3.4.2 Chemical Hazards: In some laser applications, hazardous chemicals or dyes are used, which may have serious health consequences for exposed individuals. Exposure to dyes and solvents is typically related to the weighing and mixing stages, as well as during the decontamination of the lasers. Laser dyes include xanthenes, polymethines, coumarins, and stilbenes. Some of these dyes are hazardous and possibly mutagenic with an LD50 of less than 50 mg/kg. The solvents pose a wide variety of hazards including chemical toxicity and physical hazards (i.e. fire). Proper transfer methods, adequate ventilation, personal protective equipment, process isolation, and provisions for secondary containment and labeling should be employed to reduce the potential for injury. 3.4.3 Inhalation Hazards: Lasers have the potential to generate aerosols when they come into contact with various materials. In addition, some applications require the utilization of compressed gases during their operation; therefore, additional precautions must be taken when dealing with gas cylinders and the potential explosion hazards. Medical and research lasers may generate biological aerosols, which can be inhaled or absorbed by individuals. Some lasers may require cryogenic cooling, which will include hazards associated with this type of application. 4 Laser and Laser System Classification The classification of all lasers is based on specific parameters, including: 1. wavelength(s) or wavelength range; 2. for continuous wave (CW) or repetitively pulsed lasers: average power output (Watts) within a specified limiting aperture (effective power) 3. limiting exposure duration (Tmax) of CW or repetitive-pulse lasers; 4. intended use; 5. total energy, duration, repetition frequency, and emergent beam radiant exposure per pulse. Figure 6 is a summary of laser classification. For detailed classification, refer to The ANSI standard (ANSI Z136.1-2014): 12
Class 1/1M: Lasers or laser systems that do not, under normal operating conditions, pose a hazard to personnel. These include laser printers, CD players, among others. Class 1M are considered to be incapable of producing hazardous exposure conditions during normal operation unless the beam is viewed with an optical instrument such as an eye-loupe (diverging beam) or a telescope (collimated beam). Class 2/2M: Low-power visible lasers or laser systems are incapable of causing eye injury over the duration of the blink or human bright-light aversion response (0.25 sec). These lasers can not cause eye injury under normal circumstances but may present some potential hazard if viewed directly for extended periods of time. The majority of Class 2 lasers are helium-neon devices. For Continuous Wave (CW) (400 700 nm) lasers the upper limit for Class 2 is 1 mw. Class 2M are same as class 2, however, can be hazardous if viewed with certain optical aids. Class 3R: Lasers or laser systems that normally would not cause injury to the eye if viewed within the duration of the blink or aversion response with the unaided eye, but a hazard may be present if the beam is viewed through binoculars or similar optical focusing devices. Some Class 3R lasers can be equipped with danger labels that indicate whether they are capable of exceeding maximum permissible exposure (MPE) levels for the eye within 0.25 sec, but still pose a low risk of injury. For Continuous Wave (CW) (400-700 nm) lasers the upper limit for Class 3R is 5 mw. Class 3B: Lasers or laser systems can produce accidental injuries to the eye from viewing the direct beam or a specular reflection. Class 3B lasers normally will not produce a hazardous diffuse reflection from a matte (not shiny) target unless viewed through an optical instrument. Class 3b ultraviolet (180 to 400 nm) and infrared (1400 nm to 1 x 10 6 nm) lasers cannot emit an average radiant power in excess of 0.5 W for 0.25 s or cannot produce a radiant energy greater than 0.125 J within an exposure time < 0.25 s. Class 3b visible (400 to 700 nm) or near-infrared (700 to 1400 nm) lasers cannot emit an average radiant power in excess of 0.5 W for 0.25 s and cannot produce a radiant energy greater than 0.03 J per pulse. Class 4: Lasers that present the eye and skin hazards from direct beam, specular reflections or diffuse reflections. In addition, Class 4 lasers can ignite flammable targets, create hazardous airborne contaminants and usually contain a potentially lethal high voltage supply. Class 4 lasers and laser systems are those that emit radiation in excess of Class 3b lasers. Figure 6: Laser Classification 13
All lasers are classified by the manufacturer and labelled with the appropriate warning labels. Any modification of an existing laser or an unclassified laser must be classified by the Laser Safety Officer (LSO) and approved by the Research Safety Committee prior to use. 5 Hazard Evaluation 5.1 Viewing Conditions of Laser Radiation The laser can be considered as a highly collimated source of extremely intense monochromatic electromagnetic radiation. Due to these unique beam properties, most laser devices can be considered as a light source of great brightness. Conventional light sources or a diffuse reflection of a Class 2 or Class 3 laser beam are extended sources of low brightness because the light radiates in all directions. Brightness is of considerable consequence from a hazard point of view, since the eye will focus the rays (400-1400nm) from a highly collimated laser to a very small spot on the retina, whereas the rays from an extended source will be imaged, in general, over a much larger retinal area. When one is relatively far away from a diffuse target (far enough that the eye can no longer resolve the image), the retinal exposure from a diffuse reflection approximates direct exposure to a laser beam. Diffuse reflections generally only need to be visible at IR-A radiation (400-1400nm). Intrabeam viewing refers to viewing the direct beam or beam reflected off smooth surface. Direct viewing of the beam is the most hazardous (Figure 7). Specular reflection is mirror-like reflections and can be especially hazardous if close to 100% of the incident light is reflected (Figure 8). Diffuse Reflections (extended source) result when surface irregularities scatter light in all directions. Extended source viewing produces a larger retinal image (Figure 9). Figure 7: Intrabeam viewing of a direct (primary) beam. This type of viewing is most hazardous. 14
Figure 8: Intrabeam viewing of a specularly reflected (secondary) beam from a flat surface reflector. Curved surface reflectors are hazardous albeit less so than if flat. Figure 9: Extended source viewing of a normally diffuse reflection. Diffuse reflections are not normally hazardous, except with very high power Class 4 lasers. 5.2 MPE - Maximum Permissible Exposure (J/cm2 or W/cm 2 ) for irradiance The MPE is defined in ANSI Z136.1-2007 as The level of laser radiation to which a person may be exposed without hazardous effect or adverse biological changes in the eye or skin. The MPE is not an exact limit between safe and hazardous exposures; rather it is a maximum level which various experts agree should be occupationally safe for nonphotosensitive individuals for repeated exposures. The biological effects of laser radiation are dependent on the wavelength of the laser, exposure duration and power intensity. Therefore MPE s are calculated using correction factors for these indices. The MPE has been expressed (normalized) relative to the limiting aperture area. Calculations of MPE s if required can be done with the assistance of the LSO for Class 3b and Class 4 lasers. 5.3 Nominal Hazard Zone Where unenclosed beams are required, a Nominal Hazard Zone (NHZ) needs to be defined so as to determine an area in which control measures are required. The NHZ is the space or distance within which the level of direct, reflected or scattered laser light exceeds the MPE level for the laser (Figure 10). 15
Figure 10: Example of Nominal Hazard Zone (https://uwaterloo.ca/safetyoffice/programs-and-procedures/laboratory-safety/lasers, 2015) 6 Laser Safety Program Components 6.1 Organization: Role and Responsibilities 6.1.1 Permit Holder / Laser Supervisor: The Laser Supervisor is considered the Principal Investigator and Person in Charge. The University issues an Internal Permit to a University employee who is the Principal Investigator and Person in Charge of the location where the Class 3b or Class 4 laser/laser system is used or stored. Refer to the laser classification for further information. All Laser Supervisors of Class 3b or Class 4 lasers/laser systems must meet the following requirements: Be at least 18 years of age. Be the Internal Permit holder or work under an Internal Permit. Comply with the Ontario Occupational Health and Safety Act, University Policies and Procedures, ANSI Standard for Safe Use of Lasers and follow the safe use and operation of the laser/laser system. Be familiar with the University Laser Safety Manual. Ensure that all Laser Workers under their permit complete the University Laser Safety Training Program: Laser Safety Training Course by the Chemical Control Centre (via. Third Party Provider). Additional, specific, practical training on particular lasers/laser systems must be given by the Laser Supervisor or Person 16
in Charge of the laser laboratory. Ensure all laser workers have completed the laboratory safety orientation checklist. Perform regular in-house inspections to ensure the safety of the laser system in accordance with the laser safety manual. Participate in the University Medical Surveillance program or sign a Waiver form provided by the University of Windsor 6.1.2 Laser Worker: The roles and responsibilities of Laser Workers are to: Complete the laboratory safety orientation checklist. Work as directed by their Laser Supervisors, in compliance with the Occupational Health & Safety Act and the Laser Safety Program. Participate in the Laser Safety Training course before working in the laser controlled area. Complete the laboratory safety orientation checklist. Report known or suspected accidents or safety violations to their Laser supervisors. Ensure that laser operation does not constitute a hazard to other people working in the laboratory and members of the public. 6.1.3 Team Leader, Chemical Control Centre (Laser Safety Officer) The Team Leader of the Chemical Control Centre (CCC) under the direction of the EHS Manager performs the day to day activities of the Laser Safety Officer. The CCC Team Leader provides advice and assistance in matters related to laser safety, performs laboratory inspections and assists in the administration of the Laser Safety program. The CCC Team Leader is responsible to: Maintain and provide information, advice and general training on all elements of the laser safety program; Report to the Manager of EHS on all matters pertaining to laser safety; Audit and verify work areas for compliance with certificate requirements, legislation, codes, and guidelines and submit compliance reports to the Chair and EHS Manager. Ensure that the necessary records required by applicable governmental regulations are maintained; Assist in the development and maintenance of the Laser Safety Manual and Standard Operating Procedures related to lasers; Approve purchase orders for the acquisition of lasers; Assure that adequate safety education and training are provided to laser area personnel; Recommend or approve protective equipment (i.e. eyewear, clothing, barriers, screens, etc.) as required to assure personal safety. The LSO shall assure that protective equipment is audited periodically to ensure proper working order; 17
Investigate incidents involving lasers including exposures and report the findings to the Chair and EHS Manager; Recommend and assist in the implementation of corrective actions for cases of non-compliance; and In an emergency stop any unsafe activity involving lasers when there is reason to suspect that the health and safety of University personnel, and/or the public is at risk. 6.1.4 Manager, Environmental Health & Safety (Senior Laser Safety Officer) The Manager of Environmental Health & Safety (EHS) is the designated Senior Laser Safety Officer (LSO) for the University and is responsible and accountable for the administration of the Laser Safety program to ensure that the associated activities are being performed in accordance with licence activities and the program. The Manager, EHS is responsible to: Serve on the Research Safety Committee; Maintain and provide information, advice and general training on all elements of the laser safety program; Liaise with the Ministry of Labour and other regulating agencies on matters pertaining to Laser Safety. Report to the Vice President of Research and Innovation on all matters pertaining to lasers; Audit work areas for compliance with certificate requirements, legislation, codes, and guidelines and submit compliance reports to the Chair; Assist in the development and maintenance of the Laser Safety Manual and Standard Operating Procedures related to lasers; Approve purchase orders and co-sign material transfer agreements for the acquisition and/or transfer of lasers; Investigate incidents involving lasers including exposures and report the findings to the Chair; and applicable governing body; Order corrective actions for cases of non-compliance; Order, the suspension of any activity involving lasers when there is reason to suspect that the health and safety of University personnel, the public, and/or the environment is at risk or that regulatory conditions of the project have been breached; and Liaise with local health and safety committees as applicable. 6.1.5 Research Safety Committee (RSC): The University of Windsor Research Safety Committee has the responsibility of, and authority for, establishing and enforcing the University's Research Safety Programs. The Committee formulates and reviews such programs as are necessary to ensure that the University is in compliance with guidelines and regulations outlined by the Canadian Nuclear Safety Commission (CNSC), Public Health Agency of Canada, Canadian Food 18
Inspection Agency (CFIA), The Ministry of Environment, and all applicable Federal, Provincial and municipal legislation. The Committee reviews, approves and enforces the standards through the issuance of Certificates for all work with potentially hazardous biological, radioactive, and chemical materials. The RSC is responsible for overseeing the institution s Laser Safety Program. More information on the function of the RSC can be found in the terms of reference. 6.2 Training Laser safety training is widely regarded as one of the primary preventions of laserrelated accidents. Class 3b or Class 4 laser users, including the Permit Holder, must complete the University laser safety training course offered by Chemical Control Centre. The permit holder or person in charge of the laser facility is responsible for providing practical training on particular laser equipment to all laser users. The Permit Holder must ensure that Class 3b or Class 4 laser users complete the University laser safety-training course. All laser users are responsible for the safe use of laser equipment, being familiar with the University of Windsor s laser safety manual, and following the standard operating procedures. All Class 3b or Class 4 laser users including Permit Holders must be retrained every two years. Class 1, Class 2, Class 3R, embedded Class 3b and embedded Class 4 laser users are not required to take the laser safety training course offered by the Chemical Control Centre. 6.3 Eye Protection Policy All persons assigned to or entering laser areas (Class 3b or Class 4) where eye hazards are present must wear appropriate laser eye protection when entering the nominal hazard zone for Class 3b or Class 4 lasers. Other laser protective eyewear requirements include: 1. All protective eyewear must adequately provide protection against the associated wave length of the laser. 2. All laser protective eyewear shall be clearly labelled. The associated wavelength dependent transmissive properties of the eyewear must be available to the user. 3. Laser protective eyewear shall be inspected for damage periodically and prior to use. The laser manufacturer should be consulted on the type of laser eye protection to be used. The Laser Safety Officer can also be contacted to assist if needed. Appropriate eye protection is to be provided by the Permit Holder or Person in Charge of the laser facility. Normally, The Permit Holder or Budget Unit Head is responsible to provide laser protective eyewear to Class 3b or Class 4 laser users. The Permit Holder or 19
Budget Unit Head shall contact the laser supplier for the recommended laser protective eyewear. The purchase of laser eye protectors is the responsibility of the individual budget unit. The Permit Holder or Budget Unit Head is responsible to provide laser protective eyewear to Class 3b or Class 4 laser users. The Permit Holder or Budget Unit Head shall contact the laser supplier for the recommended laser protective eyewear. 6.4 Internal Permit Procedure The University of Windsor s Radiation Safety Program issues internal permits to University employees who are either the Principle Investigator or the Person-In-Charge (i.e. AAU Head) of the location where the Class 3B or Class 4 lasers/laser systems are used or stored. 6.4.1 Application for Laser Internal Permit Procedure: 1. Applicant must be a University employee who is the Laser Supervisor or Person in Charge of the location where laser equipment is used or stored. 2. Complete the Laser Permit Application form with the approval of the Department Chair and send it to the Laser Safety Officer. The application form is available online (www.uwindsor.ca/ccc). 3. The application is reviewed and approved by the Laser Safety Officer and Research Safety Committee Chair or Designate. 6.4.2 Permit Amendment/Renewal Procedure: The Permit Holder is responsible for notifying the Chemical Control Centre in writing (i.e. email) of the following changes: 1. Lasers/laser systems (add, delete or dispose of, move, modify etc.) 2. Laser locations (add, delete, renovate, etc.) 3. Laser workers (add, delete, training, etc.) The Laser Safety Officer will confirm the changes in writing and send the updated permit to the Permit Holder. 6.4.3 Standard Operating Procedures Policy: The Permit Holder is responsible for establishing the standard operating procedures for Class 3b or Class 4 lasers. All standard operating procedures must be reviewed and determined to be acceptable to the Laser Safety Officer. The Permit Holder must ensure all laser workers follow the standard operating procedures. 20
6.4.4 Location and Operation Policy: The Permit Holder is responsible for providing to the Laser Safety Officer all information pertaining to laser equipment (new or modified) and location(s) where Class 3b or Class 4 laser equipment is installed or used. Class 3b or Class 4 equipment shall not be installed or used until the location is reviewed and determined to be acceptable to the Laser Safety Officer. 6.4.5 Purchase and Disposal Policy: Class 3b and Class 4 lasers must be reviewed and approved by the Laser Safety Officer prior to purchasing or transferring to the University. Authorized staff within the University of Windsor Purchasing Department will purchase or transfer laser equipment on behalf of the Permit Holder. The Permit Holder is responsible for notifying the Laser Safety Officer that she/he has disposed of or no longer has any Class 3b or Class 4 laser equipment. In the absence of the Permit Holder, the Department Chair will assume these duties. 6.4.6 Medical Surveillance Policy: All Class 3b or Class 4 laser users may be required to complete a baseline eye examination designed to monitor and protect their vision. This will be determined through discussion with the Laser Supervisor and the Research Safety Committee. An eye examination performed by an ophthalmologist or optometrist is necessary to establish a baseline against which damage (primary ocular) can be measured in the event of an accidental injury and to identify certain Class 3b or Class 4 laser users who might be at special risk from chronic exposure to selected continuous wave lasers. The eye examination should take place prior to participation in laser work and following any suspected laser injury. 6.5 Suspected of Known Laser Injury Any worker or researcher with a suspected injury caused by a laser affiliated with the University of Windsor must contact Health and Safety, Human Resources. 6.6 Security and Controlled Access of Class 3B and 4 Laser All Class 3b and Class 4 laser rooms are restricted access areas and must be locked at all times when unattended. Only the Permit Holder and authorized laser users listed on the permit are allowed to be left alone in the laser room when a Class 3b or Class 4 laser is in operation or can be operated. 21
All visitors must be accompanied by the Permit Holder or authorized users listed on the permit and follow all applicable regulations, policies, guidelines and procedures. 6.7 Safety Procedures Hazard controls for laser radiation vary with the following factors: 1. The laser classification 2. The environment where the laser is used 3. The people operating the laser Safety measures could be engineering control, personal protective equipment or administrative and procedural control. Engineering controls should always be the first choice. 6.7.1 Class 1 Lasers Safety Procedures: There is no known hazard for exposure to the output from a Class 1 laser or laser product. Therefore, these are truly considered to be eye safe lasers. For example, the output from a visible laser, such as a helium-neon (He-Ne) laser often used in laser scanning systems at a grocery store check-out counters, may be Class 1. If the beam from this laser product is viewed, the observer would see a red light, but because the beam is scanned, the laser product would pose no risk. Some Class 4 lasers may be contained within the protective housing in such a manner that the user is not exposed to hazardous levels of laser radiation. In his case, the laser product would be classified as Class 1 laser under normal operation, although there is a high-power embedded laser within the protective housing panels. During service, both standards require that the access panels have warning labels alerting the user of a higher power embedded laser, and/or a safety interlock preventing exposure to hazardous levels of laser radiation. 6.7.2 Class 2 Lasers Safety Procedures: These are low-power lasers that only emit visible laser radiation between the wavelengths 400 and 700nm. Therefore by definition, they are incapable of causing eye injury within the normal aversion response to bright light, which occurs within 0.25 second. At these wavelengths, an ocular hazard can only exist if an individual overcomes their natural aversion to bright light and stares directly into the laser beam. Class 2 lasers do not pose a skin hazard. The majority of low-power lasers today are gallium aluminum arsenide (GaA1As) diode lasers and helium-neon (HeNe) devices with a CW power of one milliwatt or less. A growing number of diode lasers are also found in this class. Generally speaking, a visible (400-700nm) laser beam that is comfortable to look into is below the Maximum Permissible Exposure limit (MPE). The two operational safety rules are: 22
Do not overcome the aversion response and stare into the laser beam. Do not point the laser at a person s eye. 6.7.3 Class 3 Lasers Safety Procedures: These medium power lasers usually present a serious potential for eye injury resulting from intrabeam viewing, (especially Class 3B laser beams), they generally do not represent a diffuse reflection hazard, a skin hazard, or a fire hazard. Safety procedures for Class 3R and 3b lasers are concentrated on eliminating the possibility of intrabeam viewing by: Never aiming a laser at a person s eye. Using proper laser safety eyewear if there is a chance that the beam or a hazardous specular reflection will expose the eyes. Avoid placement of the unprotected eye along or near the beam axis. Some alignment procedures may place personnel at risk by requiring close proximity to the beam where the chance of hazardous specular reflections is greatest. Attempt to keep laser beam paths above or below eye level for either sitting or standing positions. Assuring that individuals do not look directly into a laser beam with optical instruments unless an adequate protective filter is present within the optical train. Eliminate unnecessary specular (mirror-like) surfaces from the vicinity of the laser beam path, or avoid aiming at such surfaces. Do not aim the laser at doorways or windows. Additional safety procedures for Class 3b lasers include: Establish a laser control area in which the laser system is housed and all Program guidelines is followed. Ensure that individuals who operate Class 3b lasers are trained in laser safety and authorized to operate a laser. Ensure PPE is worn within the nominal hazard zone. Permit only experienced personnel to operate the laser and not leaving an operable laser unattended if there is a chance that an unauthorized user may attempt to operate the laser. A key switch should be used if untrained persons may gain access to the laser. A warning light or buzzer may be used to indicate when the laser is operating. Enclose as much of the beam s path as practical. Terminate the primary and secondary beams if possible at the end of their useful paths. Use low power settings, beam shutters and laser output filters to reduce the beam power to less hazardous levels when the full output power is not required. Assure that any spectators are not potentially exposed to hazardous conditions. Attempt to operate the laser only in a well-controlled area. For example, within a closed room with covered or filtered windows and controlled access. 23
Do not permit tracking of non-target vehicles or aircraft if the laser is used outdoors. Label lasers and room with appropriate Class 3b warning sign. Mount the laser on a firm support to assure that the beam travels along the intended path. 6.7.4 Class 4 Lasers Safety Procedures: The high-power lasers present the most serious of all laser hazards. Besides presenting serious eye and skin hazardous, these lasers may ignite flammable targets, create hazardous airborne contaminants, and may also have a potentially lethal, high current/high voltage power supply. In addition to control measures for Class 3 lasers the following rules should be carefully followed for all highpower lasers: Establish a laser control area in which the laser system is housed and all Program guidelines is followed. Enclose the entire laser beam path if possible. Confine open beam indoor laser operations to a light-tight room. Interlock entrances to assure that the laser cannot emit when the door is open. Administrative or procedural entryway safety controls may be used where interlocks are not feasible or are inappropriate; examples of administrative controls are a barrier, screen or curtain. The RSO shall review and approve alternate interlock (access) control. Ensure that all personnel wear adequate eye protection within the nominal hazard zone, or ensure that a suitable shield is present between the laser beam(s) and personnel. Use remote firing and video monitoring or remote viewing through a laser safety shield where feasible. When the laser is used outdoors, assure that the beam cannot intercept occupied areas or aircraft. Use lower power settings, a beam shutter or laser output filters to reduce the laser beam irradiance to less hazardous levels whenever the full beam power is not required. Assure that the laser device has a key-switch master control to permit only authorized personnel to operate the laser. Label lasers and room with appropriate Class 4 warning sign. Use dark, absorbing, diffuse, fire resistant target and backstops where feasible. 6.8 Laser Controlled Areas A laser hazard analysis must include the determination of a laser controlled areas, normally the research space in which the laser is housed. Within the laser controlled area resides the nominal hazard zone (NHZ), which should be calculated with assistance from the LSO, and adequate control measures must be instituted in both spaces. 24
6.8.1 Class 3B Laser Controlled Areas: A Class 3B laser controlled area shall consist of the following: A Nominal Hazard Zone in which PPE must be worn. Be confined to permit laser and laser systems to be operated by personnel who have been trained in the operation of the laser, laser system, and laser safety. Be posted with the appropriate warning sign(s). An appropriate warning sign shall be posted at the entryway(s) and, if deemed necessary by the LSO, should be posted within the controlled area (Figure 11). Be operated in a manner such that the beam path is well defined and projects into a controlled space. Have any potentially hazardous beam terminated in a beam stop of an appropriate material. Have only diffuse reflecting materials in or near the beam path, where feasible. Provide personnel within the laser controlled area with the appropriate eye protection. Have the laser secured such that the exposed beam path is above or below eye level of a person standing or seated. Ideally, the laser or laser system should be disabled when not in use to prevent unauthorized use. Figure 11: Sample warning sign for certain Class 3a, 3b and Class 4 lasers. Position 1: states precautionary or protective instructions. Position 2: describes the type of lasers, emitted wavelength, maximum output, and pulse duration if applicable. Position 3: states the laser class. 6.8.2 Class 4 Laser Controlled Areas: All Class 4 laser controlled areas must fulfill all items of Class 3b laser controlled areas. In addition, all Class 4 laser controlled areas and or entryway safety controls shall be designed to allow both rapid egress at all times and admittance to the laser controlled area under emergency situations. All individuals who require entry into a laser controlled area must participate in the University of Windsor s Laser Safety Training Program, be provided with appropriate protective equipment, and must follow all sitespecific administrative and procedural controls. 25
Emergency Controls: For emergency conditions, there shall be a clearly marked Panic Button available for deactivating the laser or reducing the output to levels at or below the applicable MPE. The Panic Button should be of the red mushroom type. Entry Controls: There are three different formats to control entry to a Class 4 Laser Controlled Area including: 1. Non-Defeatable Area; 2. Defeatable Area; and 3. Procedural Area. Non-Defeatable (non-override) Area or Entryway Safety Controls: Non-defeatable safety latches, entryway or area interlocks (i.e. electrical switches, pressure sensitive floor mats, infrared, or sonic detectors) shall be used to deactivate the laser or reduce the output to levels at or below the applicable MPE in the event of an unexpected entry into the laser controlled area. Defeatable Area or Entryway Safety Controls: Defeatable safety latches, entryway, or area interlocks shall be used if non-defeatable area/entryway safety controls limit the intended use of the laser or laser system. 6.8.3 Other Laser Controlled Areas For situations in which Class 3b and 4 lasers are to be used outside or in navigable airspace, the Laser Safety Officer should be contacted to assist in assessing the appropriate control measures. 6.8.4 Temporary Laser Controlled Areas Where removal of panels or protective housings, over-riding of protective housing interlocks, or entry into the NHZ becomes necessary (such as for service), and the accessible laser radiationexceeds the applicable MPE, a temporary laser controlled area shall be set up. This control area shall provide all safety requirements for all personnel, both within and outside the area and shall be posted outside the temporary laser controlled area to warn of the potential hazard (Figure 12). Figure 12: Sample Temporary Laser Controlled Area sign. This sign shall be posted outside a temporary controlled area, for example, during periods of service. The area 26
outside the temporary controlled area remains Class 1, while the area within is either Class 3b or 4. 6.9 Inspection of Class 3b/4 Lasers The Laser Safety Officer is responsible for conducting regular compliance audits of the University of Windsor Laser Safety Program. This audit will involve a comprehensive review of both the program and execution of the program within the respective laser laboratories. Inspection of laser equipment/facility is necessary to reduce or eliminate the risk of radiation laser incident to laser users, employees, students and the public and to comply with the applicable act and guidelines. The Permit Holder and Person in Charge of the laser facility are responsible for their own in-house inspection on a regular basis and in accordance with the laser safety manual. The Permit Holders are responsible for maintaining the engineering controls and administrative and procedural controls of their laser equipment/facility. The Laser Safety Officer will inspect all laser facility/equipment (Class 3b or Class 4) on a regular basis or at any time using the University of Windsor inspection checklist. The inspections can be announced or unannounced. All deficiencies must be corrected and reported in writing to the Laser Safety Officer. Any operations that are considered unsafe by the Laser Safety Officer will be immediately suspended. The Ministry of Labour Inspector may enter in upon any workplace at anytime without warrant or notice. All University personnel shall give a Ministry of Labour Inspector all reasonable access and assistance to carry out his/her duties and functions under the Occupational Health and Safety Act. 6.10 Compliance Enforcement Policy The University of Windsor assumes the responsibility of ensuring the Ministry of Labour that the use of laser equipment complies with the Occupational Health and Safety Act and guidelines. To aid in determining the level of risk or immediate danger to safety and health, all compliance violations will be categorized as major and minor offences. Any offence occurring twice in any one year period will be considered as a second offence and so on. Non-compliance issues will fall into two categories: Minor and Major offences. 6.10.1 Minor Offence Actions: A minor offence would be an infraction that poses no immediate risk or threat to health and safety of any person. For example, a minor offence would be one of the following 27
deficiencies: Inadequate warning signs. Standard operating procedure is not available. Failing to notify laser worker s departure. 1. First Offence: A written inspection report will be sent to the Permit Holder, copy to Department Chair,Team Leader Chemical Control Centre and Research Safety Committee Chair. The Permit Holder must take corrective action as soon as possible and a written reply must be sent to the Laser Safety Officer within 21 days of the inspection report. If the written reply is not received after 21 days, the second notice will be sent to the Permit Holder, copy to the Dean of Faculty, Department Chair,Team Leader Chemical Control Centre and Research Safety Committee Chair. A meeting will be arranged with the Permit Holder, Department Chair, Team Leader Chemical Control Centre and Laser Safety Officer if there is no response from the Permit Holder after 14 days of the second notice. 2. Second Offence: A meeting will be arranged with the Permit Holder, Department Chair, Manager Chemical Control Centre, Research Safety Committee Chair and Laser Safety Officer to review the issues. 3. Third Offence: The Laser Safety Officer will notify the Permit Holder in writing that the permit will be suspended until a meeting with the Research Safety Committee can be held. 4. Fourth Offence: The Laser Safety Officer will recommend permit cancellation to the Research Safety Committee. The RSC will contact the Office of Research Services to withhold all grant money until the offence is rectified. 6.10.2 Major Offence Actions: A major offence would result from violations that cause immediate risk or danger to health and safety of any person and/or place the Ministry of Labour Registration in jeopardy. For example, a major offence would be one of the following deficiencies: Operating laser equipment with known failed interlock. Inadequate or no training for Class 3b or Class 4 lasers. Unauthorized possession of Class 3b or Class 4 lasers. Unauthorized laser location. 1. First Offence: An inspection report will be sent to the Permit Holder, copy to the Department Chair, Team Leader Chemical Control Centre, Manager Environmental Health and Safety, and Research Safety Committee Chair. The 28
Permit Holder must take corrective action immediately and a written reply must be sent to the Laser Safety Officer within 7 days of the inspection report. If the written reply is not received after 7 days, the second notice will be sent to the Permit Holder, copy to the Dean of Faculty, Department Chair, Team Leader Chemical Control Centre, Manager Environmental Health and Safety, and Research Safety Committee Chair. A meeting will be arranged with the Permit Holder, Department Chair, Team Leader Chemical Control Centre, and Research Research Safety Committee Chair if there is no response from the Permit Holder after 7 days of the second notice. 2. Second Offence: The Laser Safety Officer will notify the Permit Holder in writing that the permit will be suspended until a meeting with the Research Safety Committee can be held. 3. Third Offence: The Laser Safety Officer will recommend permit cancellation to the Research Safety Committee. The RSC will contact the Office of Research Services to withhold all grant money until the offence is rectified. Note: For the second and third offences, notification of the above actions will be copied to the Dean of Faculty, Department Chair, Manager Environmental Health and Safety, Team Leader Chemical Control Centre and Research Safety Committee Chair. 29
Appendix 30
Appendix 1: Sample warning sign for Class 2 and Class 2M Lasers 31
Appendix 2: Sample warning sign for Class 3R, Class 3B, and Class 4 Lasers 32
Appendix 3: IEC Warning Logo and Information Label 33